Extensive work has been done in electrostatic chucks within the last ten years. An example is the chuck illustrated in U.S. Pat. No. 5,055,964, issued to the International Business Machines Corporation. The chuck disclosed herein is an improvement on that chuck. Another indication of work in wafers is an article in the IBM Technical Disclosure Bulletin Vol. 19, No. 6, November 1976 entitled "Gas Cooling". U.S. Pat. No. 3,993,123 illustrates the use of gas to conduct heat between abutting surfaces, the gas being present in the irregularities between two nominally flush surfaces and permeating the available space by diffusion from a low impedance supply area. The gas pressure is nominally atmospheric, well above a transition value characterized by the equivalence of the mean free path of the gas and the average distance between the surfaces.
A problem familiar to those in the art is the manufacture of a chuck that can withstand the hostile environment of plasma etch apparatus in which corrosive gases and high temperature will rapidly destroy chucks that have plastic insulators.
Another problem is that of fabricating a planar surface to support a semiconductor wafer and forming passages for the flow of coolant gases in the planar surface while avoiding electric breakdown through the dielectric coating between the two electrodes of a bipolar chuck such as that disclosed in the patent cited above.